To measure a fluid in a fluid container, in particular an acoustic measuring device may be used. A sound transducer of the acoustic measuring device may work both as a sound generator and as a sound receiver. To determine a height of a fluid surface or a concentration of the fluid in the fluid container, sound pulses may be emitted by the sound transducer into the fluid to be measured. The sound pulses may be reflected by an interface of the fluid to a further medium. Conclusions on properties of the fluid in the fluid container are drawn from the run time of the sound pulses.